//network is useless ,it will always use tcp4
func TfoListen(network string, listenAddr string) (listener net.Listener, err error) {
s, err := unix.Socket(unix.AF_INET, unix.SOCK_STREAM|unix.SOCK_NONBLOCK|unix.SOCK_CLOEXEC, 0)
if err != nil {
return nil, err
}
defer unix.Close(s)
err = unix.SetsockoptInt(s, unix.SOL_TCP, 23, 10)
if err != nil {
return nil, err
}
err = unix.SetsockoptInt(s, unix.SOL_SOCKET, unix.SO_REUSEADDR, 1)
if err != nil {
return nil, err
}
sa, err := kmgUnix.IPv4TcpAddrToUnixSocksAddr(listenAddr)
if err != nil {
return nil, err
}
err = unix.Bind(s, sa)
if err != nil {
return nil, err
}
err = unix.Listen(s, 10)
if err != nil {
return nil, err
}
f := os.NewFile(uintptr(s), "TFOListen")
defer f.Close()
return net.FileListener(f)
}
// TcpListen is listening for incoming IP packets which are being intercepted.
// In conflict to regular Listen mehtod the socket destination and source addresses
// are of the intercepted connection.
// Else then that it works exactly like net package net.Listen.
func TcpListen(listenAddr string) (listener net.Listener, err error) {
s, err := unix.Socket(unix.AF_INET6, unix.SOCK_STREAM, 0)
if err != nil {
return nil, err
}
defer unix.Close(s)
err = unix.SetsockoptInt(s, unix.SOL_IP, unix.IP_TRANSPARENT, 1)
if err != nil {
return nil, err
}
sa, err := IPv6TcpAddrToUnixSocksAddr(listenAddr)
if err != nil {
return nil, err
}
err = unix.Bind(s, sa)
if err != nil {
return nil, err
}
err = unix.Listen(s, unix.SOMAXCONN)
if err != nil {
return nil, err
}
f := os.NewFile(uintptr(s), "TProxy")
defer f.Close()
return net.FileListener(f)
}
// TfoListen announces on the local network address laddr using tcp protocol and fast open option.
// laddr must be in the form of "host:port".
// It returns a tfo-enabled listener and an error if any.
func tfoListen(laddr string) (lst net.Listener, err error) {
s, err := unix.Socket(unix.AF_INET, unix.SOCK_STREAM|unix.SOCK_NONBLOCK|unix.SOCK_CLOEXEC, 0)
if err != nil {
return
}
defer unix.Close(s)
sa, err := tcpAddrToSockaddr(laddr)
if err != nil {
return
}
err = unix.Bind(s, sa)
if err != nil {
return
}
// set the socket to fast open mode
err = unix.SetsockoptInt(s, unix.SOL_TCP, 23, TCP_FASTOPEN_VAL)
if err != nil {
return
}
err = unix.Listen(s, 10)
if err != nil {
return
}
f := os.NewFile(uintptr(s), "TFOListen")
defer f.Close()
return net.FileListener(f)
}
func main() {
fmt.Println("Listening on port :", port)
counter := new(connCounter)
// create socket
fd, err := unix.Socket(unix.AF_INET, unix.SOCK_STREAM, 0)
if err != nil {
log.Fatal("socket-error: ", err)
}
// sa struct
sa := new(unix.SockaddrInet4)
sa.Port = 9090
// bind
err = unix.Bind(fd, sa)
if err != nil {
log.Fatal("bind: ", err)
}
// listen
err = unix.Listen(fd, 3)
if err != nil {
log.Fatal("listen: ", err)
}
for {
connInfo := new(connection)
// accept connection, discard SA struct
newFd, _, err := unix.Accept(fd)
connInfo.fd = newFd
if err != nil {
log.Fatal("accept: ", err)
}
// client reads until closes, adding
// a gorutine allows dealing with more
// requests.
counter.mu.Lock()
counter.num += 1
counter.mu.Unlock()
fmt.Println("Number of connections: ", counter.num)
go func(c *connection, counter *connCounter) {
fmt.Printf("Conn.fd=%d\n", c.fd)
for {
// read
c.buf = make([]byte, 50)
n, err := unix.Read(c.fd, c.buf)
if err != nil {
log.Fatal("read: ", err)
}
fmt.Printf("Read: %d Value: %s\n", n, string(c.buf[0:n]))
// close
if string(c.buf[0:5]) == "close" {
_, err = unix.Write(c.fd, []byte(`Bye bye buddy`))
if err != nil {
log.Fatal("close: ", err)
}
err = unix.Close(c.fd)
if err != nil {
log.Fatal("close: ", err)
}
counter.mu.Lock()
counter.num = counter.num - 1
counter.mu.Unlock()
return
}
}
}(connInfo, counter)
}
}